Field of the Invention
The present invention relates to a vitrectomy tool and, more particularly, to a sutureless vitrectomy cutter having a cutting assembly small enough to allow the eye to heal without sutures.
Vitreous inflammatory diseases are often associated with a poor prognosis for the patient. Accurate diagnosis and early treatment of endophthalmitis and other acute forms of vitritis is essential. Traditionally, two options have been available for managing a patient with endophthalmitis. The first option is a vitreous tap which may be performed in a doctor's office or operating room. The second option is a pars plana vitrectomy which, due to the required equipment and complexity of the operation, is performed in an operating room.
While vitreous taps may be safely performed in an office setting, as well as in the operating room, many times it is difficult to aspirate liquid vitreous. This is due to the density of the vitreous cavity and the gauge of the needle (eighteen to twenty gauge) required to aspirate the vitreous. The vitreous tap has the advantage of rapid diagnosis and treatment. The major disadvantages of the vitreous tap include, but are not limited to, vitreous traction, retinal tears and/or retinal detachments.
Pars plana vitrectomy can overcome some of the problems associated with vitreous tap. Pars plana vitrectomy provides a larger vitreous sample for analysis, which may increase the diagnostic yield of organisms. It also may facilitate intraocular antibiotic penetration and allow better clearance of the toxins. The major disadvantage of the pars plana vitrectomy is that it is traditionally performed in an operating room. Operating room scheduling, rooms set-up, equipment set-up and patient admitting and testing may cause delays. Since time is of the essence with endophthalmitis, any delays in diagnosis and treatment can have devastating effects. Additionally, pars plana vitrectomy is a more difficult procedure involving several steps, and is associated with the possibility of more complications, than the vitreous tap.
After a pars plana vitrectomy is performed, it is often necessary to suture closed the opening made in the eye to perform the vitrectomy. Suturing typically involves additional problems such as increased time in the operating room and increased cost for the sutures. Sutures also increase the possibility of infection in and along the suture tract. To overcome the problems associated with suturing an eye after a vitrectomy, it is known in the art to use a vitrectomy instrument with a cutting assembly small enough to be used through an incision small enough so as not to require sutures.
These prior art sutureless pars plans vitrectomy instruments are very large, typically weighing fifty pounds or more with their transport carriage occupying five cubic feet or more of operating room space.
The size of these instruments is typically governed by the power source required to run and the need for stability during the vitrectomy procedure itself. Due to the size of these instruments, however, moving them out of the way, transporting them from room to room, or transporting them in a vehicle is cumbersome. It would therefore be desirable to provide a smaller, portable vitrectomy instrument which could be used in a doctor's office and which could be easily transported and stored.
Although the above-described techniques are adapted to provide a vitreous sample for testing, as noted above, both the vitreous tap and the pars plana vitrectomy have drawbacks for the patient. Neither technique combines the ease of the vitreous tap with the safety of the pars plana vitrectomy in a portable apparatus. The difficulties encountered hereinabove are sought to be eliminated by the present invention.